EP3216408A1 - Storage and mixing system for pasty cement components and method therefor - Google Patents

Abstract

The invention relates to a storage and mixing system for paste-like two-component polymethyl methacrylate bone cements, the storage and mixing system comprising a tubular cartridge (1) with a cylindrical interior, a cartridge head (7) which closes one end of the tubular cartridge (1), a partition wall (2) arranged axially in the cylindrical interior of the cartridge (1), the partition wall (2) being connected to the lateral surface of the cylindrical interior of the cartridge (1) and the partition wall (2) passing through the cartridge head (7) limited cylindrical interior of the cartridge (1) into two spatially separated cavities (3, 4), wherein in the first cavity (3) a first pasty cement component is contained and in the separate second cavity (4) a second pasty cement component is contained , two axially in both cavities (3, 4) of the cartridge (1) slidably disposed discharge piston (5, 6), where in which the discharge pistons (5, 6) close the two cavities (3, 4) on the side of the cavities (3, 4) opposite the cartridge head (7), the discharge pistons (5, 6) being opposite to the cartridge head (7) Rear side via a connecting means (18) are interconnected, wherein on the connecting means (18) has a wedge (22) or cone (22) with a cutting edge (20) on the cartridge head (7) facing the front of the wedge (22) or cone (22) is arranged, so that when driving the discharge piston (5, 6) in the cavities (3, 4) in the direction of the cartridge head (7), the cutting edge (20) the partition (2) cuts open and the wedge (22) or Cone (22) presses the cut parts of the partition wall (2) in the direction of the inner wall of the cartridge (1). The invention also relates to a method for mixing pasty cement components of a paste polymethyl methacrylate bone cement with such a storage and mixing system.

Description

The invention relates to a storage and mixing system for paste-like two-component polymethyl methacrylate bone cements, the storage and mixing system comprising a tubular cartridge with a cylindrical interior.

The invention also relates to a method for mixing pasty cement components of a cement paste, in particular a pasty polymethylmethacrylate bone cement, with such a storage and mixing system.

The invention thus provides a simple, inexpensive to produce storage and mixing system for paste-shaped two-component polymethyl methacrylate bone cements, with which the high-viscosity, pasty components of the polymethylmethacrylate bone cement can also be mixed and discharged with manually operated discharge devices. With the storage and mixing system, highly viscous paste-like components of two-component polymethyl methacrylate bone cements are to be mixed and discharged by means of manually operated squeezing devices.

Conventional polymethyl methacrylate bone cements (PMMA bone cements) are composed of a powdery component and a liquid monomer component ( K.-D. Kühn: Bone Cements for Endoprosthetics: An Up-to-Date Comparison of the Physical and Chemical Properties of Commercially Available PMMA Cements. Springer-Verlag Berlin Heidelberg New York, 2001 ). These polymethyl methacrylate bone cements are applied after mixing of the cement powder with the liquid monomer component in the not yet cured, paste-like state as a cement dough. When using mixing systems, the cement paste is in a cartridge in the case of powder-liquid cements. From this cartridge, the cement dough is pushed out by movement of a discharge piston. The discharge pistons usually have a diameter between 30 mm to 40 mm and thus on the outer side, on which engages the plunger of the discharge during the extrusion process, an area of 7.0 cm ² to 12.5 cm ² . The movement of the discharge piston is effected by manually operable mechanical discharge devices, also referred to as applicators. These dispensers or applicators normally have a squeezing force in the range of about 1.5 kN to 3.5N.

A recent development are paste-like two-component bone cements, as for example from the DE 10 2007 050 762 B3 , of the DE 10 2008 030 312 A1 and the DE 10 2007 052 116 B4 are known. In these two-component bone cements Two pasty cement components are stored in two separate cartridges with two separate dispensing pistons. When applying both pastes are pressed by movement of the discharge piston from the cartridges in a static mixer and discharged after mixing by a discharge pipe. With a suitable composition of the pasty cement components, a tack-free, ready-for-application cement paste is obtained immediately after the mixing of the two cement components. Waiting times to reach the tack-free of the cement dough, which inevitably occur in conventional polymethyl methacrylate bone cements, are eliminated. Valuable surgery time can be saved.

Own experiments in the context of the present invention have shown that during the Auspressvorgangs of the cartridges due to the high viscosity of the pasty cement components, a very large pressure drop takes place at the static mixer in the discharge tube. Own experiments also showed that with a conical discharge tube and a total length of about 17 cm and with an inner diameter of 11 mm at the cartridge head and using ten static mixing elements a pressing force greater than 7 kN is necessary to the high viscosity cement pastes in a for the medical users to express acceptable discharge rate.

In the application of the previous, conventional PMMA bone cements, which consist of a liquid monomer component and a separately stored cement powder component, the cement paste formed is pressed by means of manually operable discharge after mixing the two cement components in cementing or Vakuumzementiersystemen. These simple mechanical discharge devices use in particular clamping rods for squeezing, which are driven by a manually operated rocker arm. The manually driven discharge devices have been tested worldwide for decades and represent the state of the art. An advantage of these discharge devices is that the medical user has a feeling for the penetration resistance of the bone cement dough into the bone structures (spongiosa) via the hand force to be applied.

For highly viscous pasty cement components using cartridges in which the discharge pistons on the outer piston sides, on which the plungers of the discharge devices act, have a total area in the range of 7.0 cm ² to 12.5 cm ² , these devices are not or only to be operated manually with a great deal of effort. This great effort is unreasonable for medical users in the operating theater.

From the adhesive and sealant and electrically driven Auspressvorrichtungen are known. These devices can be driven both with batteries and with batteries as well as with the help of a stationary power supply. These devices can press with their sometimes very large extrusion forces particularly tough pasty masses. A disadvantage, however, in the use of electric motors that contain non-ferrous metals and are expensive to purchase. In sterile to be held surgery area such devices must be sterilized consuming or even replaced. With electrical wiring, the movement of the user in the OR can be hindered.

Furthermore, pneumatic devices have also been proposed. These devices require a stationary or mobile compressed air connection ( US 2 446 501 A ; DE 20 2005 010 206 U1 ). These compressed air hoses are necessary, which can hinder the movement of the user.

Alternatively, the use of compressed gas cartridges to provide compressed gas is possible. For this purpose, devices have been proposed in which the compressed gas flow is controlled by a valve and additionally by a second valve, the flow of viscous mass ( US 2004/0074927 A1 ; US Pat. No. 6,935,541 B1 ). In these devices, the gas cartridges are integrated in the devices. In such systems connected to compressed air or compressed gas cartridges containing a compressed gas source is always required without which the systems are no longer applicable.

The US 8,544,683 B2 discloses a cartridge system suitable for admixing a small amount to a major component. In the cartridge system, a second smaller cartridge is arranged next to a cartridge, wherein in a propulsion of a discharge piston in the larger cartridge and a discharge piston is driven in the smaller cartridge via a common connecting element. The connector thereby cuts through the cartridge walls to limit the overall length of the system. The disadvantage of this is that due to the asymmetry of the cartridge system, this tends to tilt the Austragskolben. This is particularly pronounced in the case of highly viscous pasty cement components for producing a PMMA bone cement. As a result, the cartridge system, when it is to be used with such tough cement components, during pressing and mixing requires such a high force output that this can not be done with conventional manually driven discharge devices.

A coaxial cartridge system containing a special piston system is disclosed in the patent EP1 392 450 B1 described. The cartridge system is used in building materials chemistry for the storage and mixing of paste-like Two-component sealants. The piston system disclosed therein has a cylindrical discharge plunger for the central cartridge and an annular discharge plunger for the second coaxially arranged cartridge. Both discharge pistons are driven behind the sealing surfaces via a support element which has a plurality of contact surfaces for the plunger of the discharge device on the back. The support element contains arcuate cutting edges. Upon axial action of the plunger of a squeezing device, both pistons are moved forward in the direction of the cartridge head. The paste-like components contained in the coaxial cartridges are pressed in the direction of the cartridge head. At the same time, two blades divide the wall of the inner coaxial cartridge into two parts. The disadvantage of this system is that inevitably two cutting processes take place at the same time. This means that energy has to be applied for both cutting processes, which thus does not provide the actual propulsion of the two pasty components. The mixing of paste-like cement components for PMMA bone cements requires due to the arranged in the discharge tube static mixer and the high viscosity of the cement components very much propulsion energy, which is no longer manually, safely and not apply conventional dispensing devices for larger cartridges. A loss of propulsion energy through two simultaneous cutting processes can therefore be problematic, especially in the case of highly viscous paste-like components. In addition, coaxial cartridges are not readily filled with cement components of a PMMA bone cement. In particular, if only small amounts of the PMMA bone cement are to be included, the free cross sections of the outer coaxial cartridge are so small that they can not be filled with conventional methods.

The object of the invention is therefore to overcome the disadvantages of the prior art. In particular, a simple, inexpensive to manufacture storage and mixing system for paste-like two-component polymethylmethacrylate bone cements and a method for producing a cement dough with a storage and mixing system is to be provided, wherein the storage and mixing system as a single use ready-to-use -System should be feasible in a simple manner with a minimum number of assembly steps within a few seconds ready for use and produced after connection with manually driven medical discharge devices or applicators immediately after the start of manual actuation of the discharge a homogeneously mixed cement dough and discharges at the discharge of a discharge pipe. The manually operated discharge devices previously used in the OPs for the conventional polymethyl methacrylate bone cements, each with a push rod and optionally a plate, are intended for the discharge of the two-component polymethyl methacrylate bone cement or the cement dough can be used with the storage and mixing system to be developed. This should avoid the procurement of special discharge devices for the discharge of paste-like two-component polymethyl methacrylate bone cements.

Preferably, the storage and mixing system to be developed does not require two interconnected push rods or plungers connected in synchronism, so that the entire device does not become substantially longer and larger than the mixing systems and vacuum mixing systems customary for the conventional powder-liquid polymethylmethacrylate bone cements. It should be found a simple solution that allows, as far as possible with only one push rod or ram and possibly a plate attached to expel two paste-shaped cement components synchronously and manually from the device. The pasty cement components of the bone cement should be able to be safely stored separately within the storage and mixing system. For application, both pasty cement components should be able to be safely combined. The storage and mixing system should also be able to discharge a small volume of homogeneously mixed cement dough of about 50 ml or a maximum of 70 ml, without larger residual amounts (more than 15 ml) remain in the system and must be disposed of consuming. Larger volumes of cement dough are not sought. Namely, the small amounts mentioned are sufficient for many applications, such as operations (OPs) in the region of the knee.

The transition from the cartridge to the discharge pipe should be structurally designed as possible so that the flow resistance of the paste-like cement components during pressing is as low as possible. As cement components paste cement components must be used, which are applicable immediately after pressing, so that no time is required to swell the PMMA bone cement. The device should be such that a confusion of the relevant assembly steps by the user is constructively excluded as far as possible and the storage and mixing system can also be carried out by largely untrained personnel. Furthermore, a method for mixing the paste-like cement components and for discharging the homogeneously mixed cement dough is to be provided.

1. a) eine röhrenförmige Kartusche mit einem zylindrischen Innenraum,
2. b) einen Kartuschenkopf, der ein Ende der röhrenförmigen Kartusche verschließt,
3. c) eine axial in dem zylindrischen Innenraum der Kartusche angeordnete Trennwand, wobei die Trennwand mit der Mantelfläche des zylindrischen Innenraums der Kartusche verbunden ist und wobei die Trennwand den durch den Kartuschenkopf begrenzten zylindrischen Innenraum der Kartusche in zwei räumlich voneinander getrennte Hohlräume teilt, wobei in dem ersten Hohlraum eine erste pastenförmige Zementkomponente enthalten ist und in dem separaten zweiten Hohlraum eine zweite pastenförmige Zementkomponente enthalten ist,
4. d) zwei axial in beiden Hohlräumen der Kartusche verschiebbar angeordnete Austragskolben, wobei die Austragskolben die beiden Hohlräume auf der dem Kartuschenkopf gegenüberliegenden Seite der Hohlräume abschließen,
5. e) wobei die Austragskolben an der dem Kartuschenkopf gegenüberliegenden Rückseite über ein Verbindungsmittel miteinander verbunden sind, wobei an dem Verbindungsmittel ein Keil oder Kegel mit einer Schneide an der zum Kartuschenkopf weisenden Vorderseite des Keils oder Kegels angeordnet ist, so dass beim Vortreiben der Austragskolben in den Hohlräumen in Richtung des Kartuschenkopfs die Schneide die Trennwand aufschneidet und der Keil oder Kegel die aufgeschnittene Teile der Trennwand in Richtung der Innenwand der Kartusche drückt.

The objects of the invention are achieved by a storage and mixing system for paste-like two-component polymethyl methacrylate bone cements comprising the storage and mixing system

1. a) a tubular cartridge with a cylindrical interior,
2. b) a cartridge head closing one end of the tubular cartridge,
3. c) an axially disposed in the cylindrical interior of the cartridge partition, wherein the partition wall is connected to the lateral surface of the cylindrical interior of the cartridge and wherein the partition divides the limited by the cartridge head cylindrical interior of the cartridge into two spatially separated cavities, wherein in the first cavity containing a first pasty cement component and in the separate second cavity containing a second pasty cement component,
4. d) two discharge pistons arranged axially displaceably in both cavities of the cartridge, the discharge pistons closing the two cavities on the side of the cavities opposite the cartridge head,
5. e) wherein the discharge pistons are connected to each other at the opposite side of the cartridge via a connecting means, wherein on the connecting means a wedge or cone with a cutting edge on the cartridge head facing front of the wedge or cone is arranged, so that when driving the discharge piston in the Cavities in the direction of the cartridge head, the cutting edge cuts the partition and the wedge or cone pushes the cut parts of the partition wall in the direction of the inner wall of the cartridge.

The two parts of the cut with the cutting partition thus remain connected to the cartridge. Particularly preferably, the wedge or cone deforms the two cut parts of the partition wall. The deformation causes a displacement of the material of the parts of the cut-open partition in the direction of the inner wall of the cartridge. Most preferably, the parts of the cut-open parts of the cartridge are folded in the direction of the inner wall of the cartridge.

According to the invention, the wedge or cone preferably has a diameter of at least 1.5 mm, more preferably of at least 3 mm, on the base opposite the cutting edge. This ensures that a plunger of a discharge device a sufficient contact surface for advancing the connecting means and thus the discharge piston is offered.

The cutting edge is preferably arranged perpendicular to the dividing wall and / or the cutting edge runs perpendicular to the dividing wall through the dividing wall. Furthermore, it can be provided that the cutting edge moves along the cylinder axis or in the region of the cylinder axis of the cylindrical inner space when the connecting means in the interior of the cartridge is moved axially.

The two cavities are preferably likewise cylindrical and particularly preferably have a base area in the form of a semicircle or in the form of circle segments.

The storage and mixing system is preferably intended for a 1: 1 mixture of the cement components.

It can be provided that the partition is at least half as wide as half the maximum diameter perpendicular to the axis of the cartridge. It can also be provided that the partition is a flat surface. The partition wall is intended to divide the cylindrical interior of the cartridge in the region of the axis of the interior of the cartridge into the two cavities, more preferably to divide it into two equal cavities.

With an alternative development of the present invention it is proposed that the discharge pistons consist of a plurality of non-interconnected parts, preferably a front part and a rear part, which are connectable to each other or which can be applied to each other. The front part is then simply pushed forward from the rear part in the cavities. The connecting means is connected to the rear or rearmost parts of the Austragskolben or connectable. To stabilize the two discharge pistons and to stabilize the movement of the two discharge pistons in the cavities, the two discharge pistons are preferably each made in one piece and firmly connected to the connecting means.

Preferably, it can be provided that the partition separates the interior of the cartridge liquid impermeable and thereby the two cavities are separated from each other liquid impermeable.

This ensures that the two cement components can be stored for a long time in the storage and mixing system or within the cartridge. It should be avoided that the liquid and very mobile monomer component creeps into the adjacent cavity and reacts with the other cement component.

According to a preferred embodiment of the invention can be provided that the partition wall is connected to the lateral surface of the cylindrical interior of the cartridge along two connecting lines which define the lateral surface, wherein preferably the connecting lines are arranged opposite to each other and particularly preferably the axis of the cartridge in the partition lies.

This allows a uniform propel the discharge piston in the cavities and a uniform cutting of the partition with a constant force.

It can also be provided that the side facing away from the cartridge head of the wedge or cone forms a contact surface for a plunger of a discharge device. The plunger of the discharge device is for this purpose preferably aligned in a direction in the surface of the partition, so that the pressure exerted by the plunger on the cutting edge is so pressed on the cutting edge that the cutting edge cuts through the partition and the wedge or cone can be driven through the cut in the partition. It should not come as possible to tilt the cone or wedge.

Furthermore, it can also be provided that the cavities have a semicircular or circular segment-shaped cross-section and the discharge pistons have a mating cross section, so that the discharge pistons close the cavities in any axial position in the cavities.

This allows a particularly simple and cost-effective to be implemented storage and mixing system.

According to a preferred further development of the storage and mixing system according to the invention, it can be provided that the discharge pistons are spaced apart from one another via the connecting means in such a way that the gap lying between the discharge pistons is less than or equal to the thickness of the dividing wall.

This ensures that the discharge pistons run stably in the cavities and that the dividing wall can be easily bent up by the wedge or cone.

It can also be provided that the dividing wall has a maximum thickness of 1.5 mm, preferably of not more than 1.0 mm, and / or the dividing wall has such a thickness that the dividing wall with the cutting edge on which a propulsive force of 1 kN acts to cut and bounce off the wedge or cone.

This ensures that the dividing wall, when made of conventional plastics, can be cut open easily with manually driven discharge devices while the cement components are pressed out of the cavities by the discharge plungers.

Furthermore, it can be provided that the storage and mixing system has a discharge pipe, on which a fastening means for fixing the discharge pipe to the cartridge is provided, wherein preferably the discharge pipe is to be fastened to the cartridge instead of the cartridge head.

The fastening means is preferably an internal thread which can be screwed onto an external thread on the cartridge. Particularly preferably, the external thread on the cartridge is also used for releasably securing the cartridge head to the cartridge.

In the discharge pipe according to the invention preferably a static mixer is arranged. With the invention it is also proposed that a static mixer is arranged in the discharge pipe and that an internal thread, an external thread, elements of a bayonet closure and / or latching elements of a latching closure are attached to the base of the discharge pipe as connecting means.

Hereby, the discharge pipe can be used to mix the cement components and apply them precisely. Especially in hard to reach places for the application of a PMMA bone cement a longer discharge tube is advantageous.

Static mixers are all commonly known static mixers. At the base of the discharge tube, an internal thread and / or an external thread and / or elements of a bayonet closure and / or latching elements of a latching closure are attached as connecting means. With this connecting means, the discharge pipe can be mechanically stable connected to the cartridge. This connection must be stable so that the high pressure which occurs during the pressing out of the paste-like cement components does not lead to detachment of the discharge tube from the cartridge. Particularly advantageous connecting means are threaded and very particularly advantageous are double thread.

In storage and mixing systems with discharge pipe can also be provided that the ratio of the diameter of the interior of the cartridge to the inner diameter of the discharge tube is less than 5 to 2, wherein preferably the ratio of the diameter of the interior of the cartridge to the inner diameter of the discharge tube is less than or equal to 2 is to 1 and most preferably the ratio of the diameter of the interior of the cartridge to the inner diameter of the discharge tube 8 to 5.

This ensures that during the propelling of the Austragskolben a sufficient flow rate of the PMMA bone cement is achieved at the discharge of the discharge pipe.

According to a preferred development, it can also be provided that the diameter of the interior of the cartridge is less than or equal to 25 mm, wherein preferably the diameter of the interior of the cartridge is less than or equal to 20 mm.

It may also be provided in Austragsrohr storage and mixing systems that the diameter of the interior of the cartridge is less than or equal to 25 mm and the inner diameter of the discharge tube is less than or equal to 15 mm, preferably the diameter of the interior of the cartridge is less than or equal to 20 mm and the inner diameter of the discharge pipe is less than or equal to 12 mm.

The inventive construction of the cartridge or the cartridge and the discharge tube makes it possible to accommodate both pasty cement components of the PMMA bone cement in a single cartridge, which can be pressed by manual force, and which can also be filled at the same time with conventional techniques. For larger diameters, a manual application of force is no longer readily sufficient to force the viscous cement components of the bone cement out of the cartridge.

It is also proposed according to the invention that the cartridge is constructed in one piece with the partition arranged therein, preferably the cartridge and the partition is made as a one-piece injection molded part made of plastic.

This ensures that the two cavities are tightly separated from each other, so that a longer-term storage of the cement components is possible.

Furthermore, it can be provided that the cutting edge consists of a steel alloy, aluminum alloy, zinc alloy, ceramic, a polyamide, glass fiber reinforced polyamide, polyimide, polyamide-co-imide, polyether ketone or polysulfone.

These materials are well suited for cutting the partition and inexpensive to process.

With a development of the invention, it is proposed that the ratio of the inner diameter of the cartridge to the distance of the discharge piston to the cartridge head is less than or equal to 1 to 4, wherein preferably the ratio of the inner diameter of the cartridge to the distance of the discharge piston to the cartridge head is less than or equal to 1 to 10 ,

According to a development of the device according to the invention can be provided that two bushings are provided in the cartridge head, which connect the two cavities with the environment of the storage and mixing system, wherein in each case a releasable stopper is arranged in the bushings.

This makes it possible that the cement components can be filled through the bushings in the cavities. In a variant of the present invention, the cement components can also be pressed out again through the bushings after removal of the plugs.

In preferred storage and mixing systems can also be provided that the cartridge on the side opposite the cartridge head has a fastener for a discharge and on the side of the cartridge head has at least one fastening means, in particular an external thread, an internal thread, at least one element of a bayonet closure and / or has a latching element of a latching closure as a fastening means.

This facilitates the connection of the cartridge to the squeezing device at the back or to a dispensing tube and / or a closure of the cartridge head at the front.

The discharge pistons can be used to fill the cavities with the cement components as they first abut the cartridge head. The cement components are pressed into the cavities and thereby the discharge pistons in Depressed direction of the connecting means or the back of the cartridge without undesirable air pockets remain in the interior of the cavities, which would interfere with the expulsion of the cement components with the discharge from the cavities. It can be provided locking means which connect the Austragskolben with the connecting means.

It may also be provided that the cartridge, the cartridge head, the dividing wall and the discharge flask are made of plastic, wherein as plastics polyethylene co-vinyl alcohol (EVOH), polybutylene terephthalate (PBT), polyethylene terephthalate (PET) and poly-methacrylates-co-polymer acrylonitrile are preferred.

The construction with plastics is inexpensive and easy to implement. The preferred plastics are particularly well suited because of their resistance to the chemicals contained in the cement components.

Furthermore, it can be provided that the cartridge head is realized by a rubber-elastic plate which is secured with a cap on the cartridge, the cap prevents movement of the rubber-elastic plate away from the cartridge by means of a protruding edge, and wherein the rubber-elastic plate on the side facing the discharge piston has a recess for receiving the longitudinal side of the partition, and wherein preferably two areas are defined by this recording in the rubber-elastic plate, wherein in each area a passage is arranged, which is closed by a plug.

This achieves a good sealing effect of the storage and mixing system. The division of the rubber-elastic plate in two areas is not to be understood that the rubber-elastic plate must have two separate parts. The two areas can therefore be connected and realized by a one-piece rubber-elastic plate.

It can also be provided that the cartridge head is additionally constructed with a plastic plate, wherein the plastic plate is arranged on or below the rubber-elastic plate in the cartridge head. The plastic plate serves for additional sealing and promotes the chemical resistance of the cavities thus limited to the cement components. The arrangement of the additional plastic plate leads to an improved diffusion barrier over the methyl methacrylate contained in the cement components.

Furthermore, it may be provided that a cap is provided as a connecting element for connecting the cartridge head to the cartridge, wherein the cap has an internal thread or an external thread or a bayonet catch or locking elements.

The cap is preferably a union nut and can be screwed onto the cartridge. The cap can be considered as part of the cartridge head. As a result, the cartridge head can be stably connected to the cartridge. With the connecting element, the cap can be securely connected to the cartridge. Detachment of the cartridge head from the cartridge during storage and transportation can thereby be securely prevented.

According to the invention can be provided that the cartridge head is formed of a rubber-elastic plate and a plastic cap, the cap blocked the rubber-elastic plate up by a superior edge, the rubber-elastic plate on the bottom of a recess for receiving the longitudinal side of the partition has, and by this recording, the rubber-elastic plate is divided into two semicircular surfaces, and wherein in each semicircular surface a passage is arranged, which is closed by a plug. The two bushings are required for filling the two cavities with the pasty cement components. The cap can therefore also be accepted as part of the cartridge head.

In one embodiment, the end face of the cartridge is formed as a cartridge head, wherein the underside has a recess for receiving the narrow side of the partition, which divides the end face into two semicircular surfaces, wherein in each semicircular surface a passage is arranged, which is closed with a stopper , These feedthroughs can be cylindrical, semicircular, circular segmental or even kidney-shaped. According to the geometry of these bushings are then also the plug cylindrical, semicircular, circular section or kidney-shaped. It is particularly advantageous if the plugs have latching elements on the underside, so that detachment of the plugs from the cartridge head during storage and transport of the cartridge system is effectively prevented.

It may be further provided according to the invention that the connecting means is designed such that the two cut parts of the partition wall remain connected to the inner wall of the cartridge when the connecting means is driven in the interior of the cartridge in the direction of the cartridge head.

This ensures that the two separated parts of the partition are located at defined positions in the interior of the cartridge and so there is no blockage of the propulsion. It is not possible in this way that the severed parts of the partition in the interior of the cartridge can fold, or parts of the partition perpendicular to the cylinder axis and thus can form perpendicular to the propulsion wrinkles, the one Movement of the connecting means or a plunger or plate could hinder a discharge.

The cutting edge is thus preferably not arranged according to the invention close to an inner wall of the cartridge. According to the invention, no separating means or cutting edges for separating the dividing wall are preferably provided on the regions of the connecting means located outside in the region of the inner wall of the cartridge.

1. a) Entfernen des Kartuschenkopfs von der Kartusche oder Entfernen von zumindest zwei Stopfen aus zumindest zwei Durchführungen im Kartuschenkopf, so dass die Kartusche geöffnet wird,
2. b) Aufsetzen und Verbinden eines Austragsrohrs mit der geöffneten Kartusche, wobei das Austragsrohr einen Mischer enthält,
3. c) Einsetzen der Kartusche in eine manuell zu bedienende Austragsvorrichtung, die Austragsvorrichtung aufweisend einen axial vortreibbaren Stößel zum Vortreiben der Austragskolben in den Hohlräumen der Kartusche, und
4. d) Auspressen der pastenförmigen Zementkomponenten mit Hilfe der Austragsvorrichtung durch axiales Vortreiben der Austragskolben mit dem Stößel, wodurch die Zementkomponenten in das Austragsrohr gedrückt werden, wobei die beiden Zementkomponenten durch den Mischer im Austragsrohr zu dem pastenförmigen Zementteig gemischt werden und der gemischte Zementteig aus einer Austragsöffnung des Austragsrohrs ausfließt, wobei synchron zur Bewegung der Austragskolben die Trennwand mit der Schneide in Längsrichtung der Kartusche aufgeschnitten wird und mit dem Keil oder Kegel die beiden aufgeschnittenen Teile der Trennwand in Richtung der Innenwand der Kartusche zumindest derart weit nach außen gedrückt werden, dass eine weitere Bewegung des Stößels der Austragsvorrichtung nicht durch die Teile der aufgeschnittenen Trennwand verhindert oder behindert wird.

The objects underlying the present invention are also achieved by a method for mixing pasty cement components of a paste-like cement paste, in particular a polymethylmethacrylate bone cement, with such a storage and mixing system, characterized by the following successive steps,

1. a) removing the cartridge head from the cartridge or removing at least two plugs from at least two bushings in the cartridge head so that the cartridge is opened,
2. b) fitting and connecting a dispensing tube to the opened cartridge, the dispensing tube containing a mixer,
3. c) inserting the cartridge into a manually operated discharge device, the discharge device comprising an axially driven ram for propelling the discharge piston in the cavities of the cartridge, and
4. d) extruding the pasty cement components by means of the discharge device by axially expelling the discharge pistons with the plunger, thereby pushing the cement components into the discharge tube, mixing the two cement components through the mixer in the discharge tube to the pasty cement dough and the mixed cement dough from a discharge port the discharge pipe, wherein synchronously with the movement of the Austragskolben the partition is cut with the cutting edge in the longitudinal direction of the cartridge and pressed with the wedge or cone, the two cut parts of the partition in the direction of the inner wall of the cartridge at least so far outward that another Movement of the plunger of the discharge device is not prevented or hindered by the parts of the cut partition.

The steps are preferably chronologically successive. The discharge device is preferably driven manually.

At the end of the plunger of the discharge device pointing in the direction of the cartridge, a plate can be arranged with which the discharge piston or the connection means and the wedge or cone is pressed in order to advance the discharge pistons in the cartridge. The cut-open parts of the partition then have so far pressed outward against the inner wall of the cartridge so that they can not interfere with the movement of the plate.

Before removing the cartridge head from the cartridge or removing the at least two plugs from the at least two bushings in the cartridge head, the cartridge or the cavities of the cartridge in which the cement components are stored are closed.

In the method according to the invention it can be provided that the two cut-open parts of the partition wall remain connected to the inner wall of the cartridge.

This ensures that no loose parts of the cut partition can hinder further movement of the plunger.

Furthermore, it can be provided that in order to remove the cartridge head from the cartridge in step a), a connecting element is released, which connects the cartridge head to the cartridge.

This achieves a more stable connection between the cartridge head and the cartridge. In addition, the counterpart of the cartridge, that is, a connecting element on the cartridge can also be used to connect the discharge pipe.

According to a preferred development it can be provided that the dispensing tube is connected to the cartridge by connecting the connecting element of the dispensing tube to a connecting element of the cartridge.

In this way it can be ensured that the discharge pipe does not detach from the cartridge when the cement paste is pressed out.

It can also be provided that the plunger of the discharge device presses on the side facing away from the Austragskolben side of the wedge or cone and the discharge pistons are driven via the wedge or cone and the connecting means.

This ensures that the force available through the plunger can be used with the largest possible proportion for driving the cement components as well as for cutting and separating the partition. It should be avoided that too much of the force flows into an unwanted deformation of the cartridge or a disturbing canting of the discharge piston.

Furthermore, it can be provided that the side facing away from the Austragskolben side of the wedge or cone has a contact surface for applying the front of the plunger or a plate attached thereto, which is equal to or larger than the cross section of the plunger or as the bearing surface of the plate, wherein when driving the plunger, the cross section of the plunger or the bearing surface of the plate completely from the Covering surface is covered or preferably the contact surface projects beyond the cross section of the plunger or the bearing surface of the plate.

This ensures that the movement of the plunger is not hindered by the cut parts of the partition.

Finally, it is also proposed in the context of the present invention that the applicator can be driven manually or is driven by compressed air or electrically.

Manually drivable applicators are preferred according to the invention, since they need not be connected to a compressed air source or a power source, nor must contain such.

The invention is based on the surprising finding that the cement components can be stored in a single cartridge having a cylindrical inner space when the cement components in the cartridge are separated from each other by a partition disposed in the interior of the cartridge, both discharge pistons being separated common connecting means can be driven, which cuts open the partition wall and bends open the cut parts of the partition, so that further movement of a driving ram of a discharge device is not hindered. As a result, hand-operated discharge devices can be used with only one plunger, since the necessary force due to the structure of the invention is sufficient to drive and mix the cement components and cut the partition and deform, or the necessary force can be fully inserted into these four operations. Therefore, the effort required to advance the cement components, to mix the cement components and to cut and sever the partition due to the structure of the present invention is not so great that the discharge device would be too stiff overall.

Furthermore, it has surprisingly been found that in this way a narrow cartridge with only a single discharge piston can be used to propel the two cement components. Thereby, the force necessary to mix and expel the cement components can be minimized so that a manual force applicator can be used with the storage and mixing system to drive the cement components out of the cartridge and mix them together ,

The invention is based on the idea of using only a cylindrical cartridge, instead of a plurality of side-by-side cartridges or coaxial cartridges, for the separate storage of the two pasty cement components in order to minimize the flow resistance during discharge. To avoid two push rods and two plates for driving two Austragskolben the cylindrical cartridge is equipped with an axial and axially cuttable partition wall, which is the interior of the cartridge, which is delimited by two discharge pistons and a cartridge head, divides into two cavities in which the two pasty cement components can be stored separately. By cutting and bending the partition also smaller amounts of PMMA bone cement can be used and even narrower cartridges with interiors with smaller inner diameters are still auspressbar.

In a first embodiment, the cartridge head is removed and the dispensing tube containing a static mixer is connected directly to a connector to the cartridge. Immediately thereafter, the cartridge is connected to the connected discharge pipe with a manually operated discharge device or a manually operable applicator and started with the discharge of the cement components or the cement dough. These steps require about 3 to 8 seconds of time. After about 30 seconds of continuous actuation of the squeezing device or of the applicator, in the case of a total volume of both pasty cement components of not more than 60 ml, the discharge of the cement paste, ie of the mixed pasty two-component PMMA bone cement, is complete.

In a second embodiment, after removal of the dividing wall, two plugs on the cartridge head are removed and the discharge tube is connected to the cartridge by means of a static mixer with a connecting element.

The invention is also based on the idea that an axially displaceably arranged in the first cavity first Austragskolben and in the second cavity an axially movable second Austragskolben are arranged. Between the discharge piston is the partition. At the back of the Austragskolben these are connected to each other via a connecting element. The front side of the connecting element is designed as a vertical standing to the partition edge. On the back of the connecting element, a wedge-shaped or conical spacer is arranged, whose rear side is formed as a contact surface for the plunger of a discharge device. During the forward movement of the connecting means by the action of the plunger in the direction of the cartridge head, a longitudinal cut is made in the dividing wall by the cutting edge behind the discharge plunger and the two cut parts of the dividing wall remain connected to the inner wall of the hollow cylinder. The two halves of the longitudinal partition wall are forced outward by the wedge-shaped or conical spacer to the inner wall of the cartridge. As a result, the plunger can be placed on the contact surface and, over the entire length of the cartridge, press the discharge pistons forward while pressing out the paste-like cement components. By setting only one section on the partition wall, only a small part of the propulsion energy is expended, so that the majority of the propulsion energy is used to propel the propulsion energy Austragskolben and for driving and mixing the cement components is available.

Furthermore, the invention is based on the observation that highly viscous cement dough from cylindrical cartridges can be discharged by a discharge tube with static mixer with commercially operated Auspressvorrichtungen or applicators in an acceptable time and with acceptable, since manually aufbringbarem force when the discharge piston on its front side a diameter of a maximum of 25 mm. With the construction according to the invention, a cartridge system is provided which can realize such small diameters for the application of highly viscous cement components. In this case, the cartridge or the cavities can still be filled without too much effort with the cement components.

1. a) einem röhrenförmigen Hohlkörper als Kartusche,
2. b) einem Kartuschenkopf, der ein Ende des röhrenförmigen Hohlkörpers verschließt,
3. c) einer axial im röhrenförmigen Hohlkörper angeordneten Trennwand, wobei die Trennwand den Innenraum des Hohlkörpers in einen ersten Hohlraum und einen zweiten Hohlraum trennt,
4. d) einem halbkreisförmigen ersten Austragskolben, der axial beweglich im ersten Hohlraum angeordnet ist,
5. e) einem halbkreisförmigen zweiten Austragskolben, der axial beweglich im zweiten Hohlraum angeordnet ist,
6. f) einem Verbindungsmittel, das die Rückseite des ersten Austragskolbens mit der Rückseite des zweiten Austragskolbens verbindet, wobei das Verbindungsmittel die Austragskolben so beabstandet, dass der zwischen den Austragskolben liegende Spalt kleiner oder gleich der Dicke der Trennwand ist, wobei an der Vorderseite des Verbindungsmittels eine Schneide angeordnet ist, die senkrecht zum Spalt zwischen dem ersten Austragskolben und dem zweiten Austragskolben steht, wobei an der Rückseite des Verbindungsmittels ein keilförmiger oder kegelförmiger Abstandhalter angeordnet ist, dessen Rückseite als Anlagefläche für den Stößel der Austragsvorrichtung ausgebildet ist,
7. g) wobei die Dicke beziehungsweise Stärke der Trennwand kleiner oder gleich 1,5 mm ist, und
8. h) dass bei der Vorwärtsbewegung des Verbindungsmittels in Richtung des Kartuschenkopfs durch die Schneide hinter dem ersten Austragskolben und dem zweiten Austragskolben ein Längsschnitt in der Trennwand hinter den Austragskolben gesetzt wird und die beiden geschnittenen Teile der Trennwand jeweils mit der Innenwand des Hohlzylinders verbunden bleiben.

An exemplary inventive storage and mixing system for paste-like two-component polymethyl methacrylate bone cement is composed of

1. a) a tubular hollow body as a cartridge,
2. b) a cartridge head closing one end of the tubular hollow body,
3. c) a partition wall arranged axially in the tubular hollow body, wherein the dividing wall separates the interior space of the hollow body into a first hollow space and a second hollow space,
4. d) a semicircular first discharge piston, which is arranged axially movable in the first cavity,
5. e) a semicircular second discharge piston, which is arranged axially movable in the second cavity,
6. f) a connecting means connecting the back of the first discharge piston to the back of the second discharge piston, the connecting means spacing the discharge plungers so that the gap between the discharge plungers is less than or equal to the thickness of the dividing wall, wherein at the front of the connection means Cutting edge is arranged, which is perpendicular to the gap between the first discharge piston and the second discharge piston, wherein at the back of the connecting means, a wedge-shaped or conical spacer is arranged, whose rear side is formed as a contact surface for the plunger of the discharge device,
7. g) wherein the thickness or thickness of the partition is less than or equal to 1.5 mm, and
8. h) that during the forward movement of the connecting means in the direction of the cartridge head through the cutting edge behind the first discharge piston and the second discharge piston, a longitudinal section is set in the partition behind the discharge piston and the two cut parts of the partition each remain connected to the inner wall of the hollow cylinder.

It is advantageous if the wooden cylinder is integrally formed with the partition wall. Elaborate assembly steps for inserting a separate partition in the hollow cylinder thereby eliminated. When using suitable plastics, it is ensured that the two cavities are liquid-impermeable. In principle, it is also possible to use a separately prepared partition in the hollow cylinder. The partition used can then be connected by mechanical jamming or by welding or by gluing to the hollow cylinder.

The highly viscous cement components of polymethyl methacrylate paste bone cements contain the very volatile, free-radically polymerizable monomer methyl methacrylate. For storage of the cement components, it is therefore essential that the inner walls of the cartridge, the cartridge head, the discharge piston and the partition wall are formed of plastics, which are a good diffusion barrier for methyl methacrylate. Polyethylene-co-vinyl alcohol (EVOH), polybutylene terephthalate (PBT), polyethylene terephthalate (PET) and poly-methyl methacrylate-co-acrylonitrile are preferred as plastics. In addition, it is also possible to apply diffusion-proof metal layers, metal or Halbmetalloxidschichten or plastic layers on the parts not touching the cement components. In particular aluminum layers are considered as metal layers. Silica layers are particularly suitable as Halbmetalloxidschichten.

The Austragskolben or alternatively the connecting means advantageously have locking elements which can lock with counter-locking elements of the inside of the hollow cylinder of the cartridge. These locking elements prevent an opposite to the cartridge head movement of the discharge piston. The prevention of this backward movement is necessary if the cartridge system filled with the cement components is externally sterilized with ethylene oxide. Ethylene oxide sterilization applies vacuum to remove air from the sterilization chamber. Due to the negative pressure may occur due to the evaporation of methyl methacrylate in the cement components to an overpressure in the cavities and thus to an undesirable movement of the Austragskolbens opposite to the cartridge head.

It is particularly important that the inner diameter of the cartridge is less than or equal to 25 mm, so that the necessary extrusion pressure for pressing and mixing the cement components is not too high.

1. a) Entfernung des Kartuschenkopfs von der Kartusche oder Entfernen von Stopfen aus den Durchführungen des Kartuschenkopfs,
2. b) Verbinden eines Austragsrohrs, das einen statischen Mischer enthält, mit der geöffneten Kartusche,
3. c) Verbinden der Kartusche mit einer manuell zu betätigenden Auspressvorrichtung beziehungsweise Austragsvorrichtung,
4. d) manuelle Betätigung der Auspressvorrichtung beziehungsweise Austragsvorrichtung, wobei der Stößel auf eine Anlagefläche des Verbindungsmittels drückt, wobei die pastenförmige erste Zementkomponente aus dem ersten Hohlraum durch den ersten Austragskolben und die pastenförmige zweite Zementkomponente aus dem zweiten Hohlraum durch den zweiten Austragskolben in das Austragsrohr und den statischen Mischer gepresst wird, wobei der gemischte Zementteig an der Öffnung des Austragsrohrs austritt, und
5. e) wobei synchron zur Vorwärtsbewegung der Austragskolben die Schneide die Trennwand hinter den Austragskolben in Längsrichtung aufschneidet, wobei die geschnittenen Teile der Trennwand mit der Innenwand des Hohlzylinders verbunden bleiben und hinter der Schneide durch den keilförmigen oder kegelförmigen Abstandhalter so nach außen in Richtung der Innenwand des Innenraums der Kartusche gedrückt werden, dass der Stößel der Austragsvorrichtung nicht in seiner Vorwärtsbewegung in Richtung Kartuschenkopf behindert wird.

An exemplary method according to the invention for mixing the pasty cement components of the paste-like polymethyl methacrylate bone cement with the cartridge system can be implemented, for example, as follows:

1. a) removal of the cartridge head from the cartridge or removal of plugs from the lead-throughs of the cartridge head,
2. b) connecting a dispensing tube containing a static mixer to the opened cartridge,
3. c) connecting the cartridge to a manually operated squeezing device or discharge device,
4. d) manual actuation of the squeezing device or discharge device, wherein the plunger presses on a contact surface of the connecting means, wherein the pasty first cement component from the first cavity through the first discharge piston and the paste-like second cement component from the second cavity through the second discharge piston into the discharge tube and the static mixer is pressed, wherein the mixed cement dough emerges at the opening of the discharge pipe, and
5. e) in synchronism with the forward movement of the discharge piston, the cutting edge cuts the partition behind the discharge piston in the longitudinal direction, the cut parts of the partition remain connected to the inner wall of the hollow cylinder and behind the cutting edge through the wedge-shaped or conical spacer so outward towards the inner wall of the Interior of the cartridge are pressed, that the plunger of the discharge device is not hindered in its forward movement in the direction of the cartridge head.

In a variant of this method, in steps d) and e), a squeezing device driven by compressed air or by electric current is used instead of the manually driven squeezing device.

• Figur 1: eine schematische perspektivische Querschnittansicht eines erfindungsgemäßen Lagerungs- und Mischsystems;
• Figur 2: eine schematische perspektivische Querschnittansicht durch das erfindungsgemäße Lagerungs- und Mischsystem nach Figur 1 unmittelbar vor der Applikation des PMMA-Knochenzements, bei dem ein Austragsrohr an der Kartusche befestigt ist;
• Figur 3: eine schematische perspektivische Explosionsdarstellung mit teilweise unterschiedlichen und alternativen Teilen von erfindungsgemäßen Lagerungs- und Mischsystemen, wobei links unten das zusammengesetzt System dargestellt ist;
• Figur 4: eine vergrößerte schematische perspektivische Querschnittansicht des Kartuschenbodens des erfindungsgemäßen Lagerungs- und Mischsystems nach den Figuren 1 und 2;
• Figuren 5 bis 8: schematische, teilweise geschnittene perspektivische Ansichten des Kartuschenbodens des erfindungsgemäßen Lagerungs- und Mischsystems nach den Figuren 1, 2 und 4 in unterschiedlichen Stadien während des Einsetzens des Verbindungsmittels und während des Vortreibens der Austragskolben;
• Figur 9: eine schematische perspektivische Querschnittansicht auf den vorderen Teil des erfindungsgemäßen Lagerungs- und Mischsystems nach den Figuren 1, 2 und 4 bis 8;
• Figuren 10 und 11: zwei schematische perspektivische Ansichten auf ein Verbindungsmittel für ein erfindungsgemäßes Lagerungs- und Mischsystem;
• Figur 12: eine schematische Querschnittansicht durch das Verbindungsmittel nach den Figuren 10 und 11; und
• Figuren 13 und 14: zwei schematische, teilweise geschnittene perspektivische Ansichten des Kartuschenbodens des erfindungsgemäßen Lagerungs- und Mischsystems nach den Figuren 1, 2 und 4 bis 9, das in eine Austragsvorrichtung zur Umsetzung eines erfindungsgemäßen Verfahrens eingesetzt ist.

In the following, further embodiments of the invention will be explained with reference to fourteen diagrammatically illustrated figures, without, however, limiting the invention. Showing:

• FIG. 1 a schematic perspective cross-sectional view of a storage and mixing system according to the invention;
• FIG. 2 : A schematic perspective cross-sectional view through the storage and mixing system according to the invention FIG. 1 immediately prior to application of the PMMA bone cement with a dispensing tube attached to the cartridge;
• FIG. 3 a schematic exploded perspective view with partially different and alternative parts of storage and mixing systems according to the invention, wherein the composite system is shown on the bottom left;
• FIG. 4 FIG. 2: an enlarged schematic perspective cross-sectional view of the cartridge bottom of the storage and mixing system according to the invention according to FIGS FIGS. 1 and 2 ;
• FIGS. 5 to 8 : schematic, partially sectioned perspective views of the cartridge bottom of the storage and mixing system according to the invention according to the FIGS. 1 . 2 and 4 at different stages during the insertion of the connecting means and during the propelling of the discharge pistons;
• FIG. 9 a schematic perspective cross-sectional view of the front part of the storage and mixing system according to the invention according to the FIGS. 1 . 2 and 4 to 8 ;
• Figures 10 and 11 two schematic perspective views of a connecting means for a storage and mixing system according to the invention;
• FIG. 12 a schematic cross-sectional view through the connecting means according to the Figures 10 and 11 ; and
• Figures 13 and 14 two schematic, partially sectioned perspective views of the cartridge bottom of the storage and mixing system according to the invention according to the FIGS. 1 . 2 and 4 to 9 , which is used in a discharge device for implementing a method according to the invention.

In the figures, the same reference numerals are used for simplicity for the same and similar components of different embodiments partially.

FIG. 1 shows a schematic perspective cross-sectional view of a storage and mixing system according to the invention. The storage and mixing system has as a central part of a cylindrical cartridge 1, in which a partition wall 2 connects two opposite inner sides of the inner wall of the cylindrical cartridge 1. The cartridge 1 and the partition wall 2 are constructed in one piece as a common injection molded part. The partition 2 separates the interior of the cartridge 1 into two separate and fluid-tightly isolated cavities 3, 4, in which the two pasty starting components of a PMMA bone cement store.

On the back (in FIG. 1 right), the cavities 3, 4 bounded by two discharge pistons 5, 6, wherein the discharge piston 5, 6 are axially displaceable in the two cavities 3, 4 slidably. FIG. 4 shows a detail view in the form of an enlarged schematic perspective partial cross-sectional view of the cartridge bottom of the storage and mixing system according to the invention FIG. 1 , At the discharge piston 5, 6 opposite front of the storage and mixing system, the two cavities 3, 4 closed by a cartridge head 7 in the form of a rubber-elastic plate 7. The cartridge head 7 is attached to the front side of the cartridge 1 with a plastic union nut 8. In the cartridge head 7 two bushings are provided, which are each closed with a plug 9. Through the two passages, the cavities 3, 4 are accessible when the plug 9 are not inserted therein. FIG. 9 shows a schematic perspective cross-sectional view of the front part of the storage and mixing system according to the invention as a detailed view, wherein the storage and mixing system in FIG. 9 through the cartridge head 7 and the plugs 9 therein as in FIG FIG. 1 closed is.

At the back of the cartridge 1 and the bottom side (in FIG. 1 right), a connection 10 with fastening elements 12 is arranged on the cartridge 1. About the terminal 10 and the fasteners 12, the cartridge 1 to a discharge device or an applicator (in FIG. 1 not shown). At the opposite front (in FIG. 1 left) of the cartridge 1, the cartridge head 7 is attached to the union nut 8 by an internal thread 16 of the union nut 8 is screwed onto an external thread 14 on the cartridge 1. The rubber-elastic plate 7 or the cartridge head 7 seals the cavities 3, 4 from the front.

The cartridge 1 has an outer diameter of 22 mm, an inner diameter of 20 mm and a length of about 18 cm.

The two Austragskolben 5, 6 are connected to each other at the rear via a connecting means 18. For this purpose, the connecting means 18 extends with two cylinder-segment-shaped ends pointing in the direction of the cartridge head 7 into suitable cavities in the rear sides of the discharge pistons 5, 6. A pointing in the direction of the partition wall 2 front edge of the connecting means 18 is designed as a blade with a cutting edge 20 which widens in the direction of the back of the storage and mixing system via a wedge 22 or cone 22 or wedge-shaped and partially cone-shaped. At the back of the wedge 22 or cone 22, the connecting means 18 as a contact surface 23 for a plunger of a discharge device (not shown) formed.

The discharge pistons 5, 6 are sealed by two circumferential seals 24 made of rubber against the inner wall of the cartridge 1 and against the partition wall 2. The discharge pistons 5, 6 are each connected to a releasable latching element 26 with matching counter-latching elements (in the form of two recesses) in the inner wall of the cartridge 1. The discharge pistons 5, 6 can be pressed by a pressure from the back of the cartridge 1 (in FIG. 1 from the right) toward the front of the cartridge 1 (in FIG. 1 left) are thus pressed in the direction of the cartridge head 7. By means of a bottom-side pressure on the discharge pistons 5, 6, when the cartridge head 7 or at least the plugs 9 are removed, the latching elements 10 can be easily detached and, above all, serve to ensure that the discharge pistons 5, 6 fill the interior of the cartridge 1 can not be pushed out of the cartridge 1 with the cement components on the bottom side, or not over the desired, defined by the counter-locking elements in the inner wall of the cartridge 1 in the direction of the cartridge bottom (in FIG. 1 right) can be pressed.

FIG. 2 shows a schematic perspective cross-sectional view through the storage and mixing system according to the invention according to FIG. 1 immediately before the application of the PMMA bone cement, in which a dispensing tube 28 is screwed onto the external thread 14 of the cartridge 1. In the discharge pipe 28, a static mixer 30 is provided with a plurality of turns and mixing elements for mixing the cement components. The discharge pipe 28 may also be longer than that in FIG. 2 shown dispensing tube 28 to make more difficult to reach areas more easily accessible, as may be helpful for example in operations on the hip. In FIG. 2 are all parts, shown cut except for the static mixer 30, while the static mixer 30 projects in perspective out of the cutting plane.

The cement components are mixed by being forced through the discharge tube 28 and thus through the static mixer 30. The thus prepared and mixed cement dough exits via a discharge opening 32 at the tip of the discharge tube 28. The dispensing tube 28 has an internal thread 34 which fits on the external thread 14 of the cartridge 1, so that the dispensing tube 28 can be stably and firmly connected to the cartridge 1. Between the discharge pipe 28 and the front of the cartridge 1, a sealing ring 36 is arranged so that the cement components can not escape between the discharge pipe 28 and the cartridge 1. Via the threads 14, 34 and the sealing ring 36, a pressure-stable and pressure-tight connection between the discharge pipe 28 and the cartridge 1 is achieved.

The propulsion of the discharge piston 5, 6 is via a discharge device (in FIG. 2 not shown) which is connected to the terminal 12 and with which a plunger (see Figures 13 and 14 ) or a push rod of the discharge can be driven manually in the direction of the discharge pipe 28. The plunger then presses on the contact surface 23, so that on the one hand the discharge pistons 5, 6 are driven in the direction of the discharge pipe 28 and on the other hand, the cutting edge 20 is driven into the partition wall 2 and this cuts open. The pressure of the plunger solves the locking elements 10 and drives the discharge piston 5, 6 forward. The discharge piston 5, 6 close tightly with the Inner walls of the cartridge 1 and the partition 2 from. As a result, the contents of the cavities 3, 4 of the cartridge 1, namely the two pasty cement components contained, can be expelled forward through the discharge pipe 8.

FIG. 3 shows a schematic exploded perspective view with partially different and alternative parts of storage and mixing systems according to the invention. The structure of the storage and mixing systems is analogous to the storage and mixing system described above. At the bottom left, a composite storage and mixing system according to the invention is also shown in a schematic perspective view.

In FIG. 3 two alternative variants of the rubber-elastic plates 7 are shown as cartridge heads 7 with differently shaped passages, which can be closed with different plugs 9. The first variant already in FIG. 1 is shown in FIG. 3 shown lower left relative to the second variant.

In each of the two bushings, a plug 9 can be inserted and latched. The rubber-elastic plates 7 and the plugs 9 are suitable for the construction of cartridge heads 7 storage and mixing systems according to the invention. The rubber-elastic plates 7 differ in the shape of their passages and in the shape of the plug 9, which close these passages. In the first variant (variant bottom left), the bushings and the plug 9 in cross-section are semicircular or crescent-shaped. In the second variant (variant right above the first variant), the passages and the plugs 9 are circular in cross section. In the first variant, the free cross section for filling the two cement components is greater than in the second variant. For this, in the second variant, the geometry is adapted to filling tubes or syringes (not shown), via which the cement components are filled into the cavities 3, 4, so that the filling tubes or syringes close tightly with the passages. The plugs 9 can also be removed to discharge the cement components again from the cavities 3, 4 of the cartridge 1, if not the entire cartridge head 7 is to be removed.

At the two in FIG. 3 shown variants may be placed on the rubber-elastic plates 7 to the pointing into the interior of the cartridge 1 sides flat plastic discs (not shown). These plastic discs serve on the one hand to stabilize the shape of the rubber-elastic plates 7 and on the other hand to improve the chemical stability of the container or the cavities 3, 4 for the cement components.

The structure of the tubular cartridge 1 with the partition wall 2, the terminal 10, the fastening elements 12 and the external thread 14, is the same in all variants shaped. On the external thread 14 of the cartridge 1, both the union nut 8 and the discharge pipe 28 are screwed. Variants are also conceivable in which the rubber-elastic plate 7 is fixedly connected to the cartridge 1 or is not designed to be rubber-elastic and / or in one piece with the cartridge 1. Then no union nut 8 is needed and the discharge pipe 28 can be easily screwed onto the cartridge 1 after removing the plug 9. The cement components can then simply be forced through the bushings into the discharge tube 28 where they are mixed with the static mixer 30 to form the desired cement dough.

The FIGS. 5 to 8 show schematic, partially sectioned perspective views of the cartridge bottom of the storage and mixing system according to the invention according to the FIGS. 1 . 2 and 4 at different stages during the propelling of the discharge pistons 5, 6 FIG. 5 the connecting means 18 is not yet inserted into the bottom of the cartridge 1 and the discharge piston 5, 6 not yet locked in its final position. Namely, the latching means 26 of the discharge pistons 5, 6 engage in recesses 38 in the inner wall of the cartridge 1 when they are pushed into the cavities 3, 4 of the cartridge 1 sufficiently deep in the direction of the rear side of the storage and mixing system. The locking means 26 thereby block a further movement of the discharge pistons 5, 6 in the direction of the back of the storage and mixing system, while they are movable in a movement in the direction of the cartridge head 7. In the partition wall 2, a notch is provided in the direction of the connecting means 18, by means of which the cutting edge 20 can more easily slide into the desired cut in the dividing wall 2 and the beginning of the cut is defined.

In the in FIG. 6 shown position, the discharge piston 5, 6 are engaged with the locking means 26 in the recesses 38 and the connecting means 18 is the bottom side in the discharge piston 5, 6 inserted and connects them. The storage and mixing system is thus ready for use. The cartridge head 7 can be separated or the plugs 9 can be removed from the bushings in the cartridge head 9 and instead of the union nut 8, the discharge pipe 28 is screwed onto the cartridge 1. In this position, a discharge device with the terminal 10 and the attachment means 12 of the storage and mixing system can be connected.

The connecting means 18 is driven by a pressure on the contact surface 23 in the direction of the cartridge head 7. This situation, together with the essential parts of a discharge device for driving the connection means in FIG. 13 shown. The latching means 26 are released from the recesses 38 and the discharge pistons 5, 6 are pushed forward in the cavities 3, 4. The two cement components are pressed forward in the discharge pipe 28 and mixed there. In a further propulsion of the connecting means 18 not only the discharge pistons 5, 6 continue in the cavities 3, 4 of the cartridge 1, but the cutting edge 20 also engages in the notch of the partition 2 and begins to cut it in the axial direction. This situation is in the FIGS. 8 (without dispenser) and 14 (with parts of a dispenser).

By further driving the connecting means 18, the wedge 22 or cone 22 arranged behind the cutting edge 20 presses the cut-open parts 40 of the dividing wall 2, which are still connected to the inner wall of the cartridge 1, and presses them in the direction of the inner wall of the cartridge 1. Meanwhile, the cement components are further pressed from the cavities 3, 4 in the discharge pipe 28 and mixed there. Finally, the ready-mixed cement dough passes out of the discharge tube 28 through the discharge opening 32 and can be applied at the desired location.

As in FIG. 9 it can be seen, the plugs 9 have a detent 42 in the form of projections which engage over the edge of the passages in the direction of the interior of the cartridge 1 in the cartridge head 7 and thereby engage with the cartridge head 7. By the latching 42 it is achieved that the plugs 9 do not unintentionally detach from the cartridge head 7.

Figures 10 and 11 show two perspective views of a connecting means 18 for a storage and mixing system according to the invention and FIG. 12 a schematic cross-sectional view through the connecting means 18 after the Figures 10 and 11 , The connecting means 18 roughly has the shape of a yoke and has a twofold rotational symmetry and a mirror plane as the plane of symmetry, the twofold rotational symmetry axis lying in the mirror plane. When installed, the twofold rotational symmetry axis coincides with the axis of the cartridge 1, that is to say with the cylinder axis of the cartridge 1.

The cartridge head 7 facing side of the connecting means 18 consists of two cylinder segments which are cut in a plane parallel to the cylinder axis, wherein on the lateral surface of the cylinder segments two recesses 44 are arranged as counter detents 44 for a respective latching means in the discharge piston 5, 6 , The two cylinder segments of the connecting means 18 thus engage with the discharge pistons 5, 6 when they are inserted into the openings provided on the rear side of the discharge pistons 5, 6 opposite the cartridge head 7.

The two cylinder segments are connected to each other via a plate, in the middle of which a central vertical cylinder is arranged with a circular base surface 23, the contact surface 23 for a plunger 48 (see Figures 13 and 14 ) forms a discharge device. On the opposite side of the central cylinder, the base is chamfered and forms the wedge 22 or cone 22. At the top of the wedge 22nd or cone 22, the cutting edge 20 is arranged, which bridges the gap between the two cylinder segments. The two cylinder segments are held by the plate and the central vertical cylinder at a fixed distance from each other. The distance is chosen so that the two discharge pistons 5, 6, when they are plugged onto the cylinder segments of the connecting means 18, are held at a distance from each other, which is slightly smaller or at most as large as the thickness of the partition wall 2, ie for example, 1 mm. The cutting edge 20 may be a hard metal or hard plastic insert, or the entire connecting means 18 may be made of such a material that must be hard enough to be able to cut the dividing wall 2 when the connecting means 18 in the cartridge 1 is driven in the direction of the cartridge head 7.

The Figures 13 and 14 show two schematic, partially sectioned perspective views of the cartridge bottom of the storage and mixing system according to the invention according to the FIGS. 1 . 2 and 4 to 9 , wherein the storage and mixing system is used in a discharge device for implementing a method according to the invention. From the discharge device is in the Figures 13 and 14 only one port 46 for connection to the mounting means 12 of the storage and mixing system, a plunger 48 and a bearing 50 for the plunger 48 shown. These parts and the remaining components of the discharge device correspond to those of conventional manually or electrically or pneumatically driven discharge devices. The discharge device has a compartment for receiving the storage and mixing system, wherein the storage and mixing system is kept stable at least at the front in the region of the thread 14 and at the back of the terminal 10. The terminal 46 is connected to the attachment means 12. The plunger 48, which acts as a push rod 48, can be moved or driven against the connection 46 of the discharge device in the direction through the connection 46 or in the direction of the cartridge 1 since it is movably mounted in the storage 50 along its longitudinal axis. In this case, the tip of the plunger 48 presses against the contact surface 23 of the connecting element 18. As a result, the connecting element 18 and the two discharge pistons 5, 6 are driven in the direction of the discharge pipe 28.

By the spreading of the two cut partition parts 40 by means of the wedge 22 or cone 22 of the connecting means 18, the partition wall parts 40 are pressed toward the inner wall of the cylindrical interior of the cartridge 1 and away from the plunger 48 moving inside the cartridge 1. As a result, the two cut-partition parts 40 can not hinder the further movement of the plunger 48. This makes it possible, despite the high toughness of pasty cement components, despite the flow resistance caused by the static mixer 30 and despite the force required to cut the partition wall 2 by the cutting edge 20 or energy expenditure of the resistance to the movement of the plunger 48 is not so great that the cartridge 1 is not squeeze with conventional and manually driven discharge devices.

Cartridge 1 and connector 10 are preferably made in one piece in all variants and are preferably made of plastic. Except for the seals 24, all parts of the storage and mixing systems can be made by injection molding of plastic. The seals 24 are preferably made of rubber. Also, the plate 7 for the cartridge head 7 may be made of rubber or a rubber-elastic material. The cutting edge 20 is preferably made of a metal, a ceramic, a metallic alloy or a particularly hard plastic. Theoretically, the other parts of the storage and mixing systems can be made of metallic materials. The cement components used are preferably pasty starting components of a PMMA bone cement. Theoretically, however, other cements, such as dental cements, two-component adhesives or other two-component systems, which are mixed from pasty starting components, stored and mixed with a storage and mixing system according to the invention.

The features of the invention disclosed in the foregoing description, as well as the claims, figures and embodiments may be essential both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

1

cartridge

2

partition wall

3

cavity

4

cavity

5

delivery plunger

6

delivery plunger

7

cartridge head

8th

Nut

9

Plug

10

connection

12

fastener

14

external thread

16

inner thread

18

connecting means

20

cutting edge

22

Wedge / cone

23

contact surface

24

poetry

26

latching means

28

discharge pipe

30

Static mixer

32

discharge

34

inner thread

36

poetry

38

Counter latch / recess

40

Slit partition

42

latching

44

Deepening / counter-locking

46

connection

48

Plunger / push rod

50

storage

Claims (15)

Storage and mixing system for paste-like two-component polymethyl methacrylate bone cements, having the storage and mixing system
a tubular cartridge (1) with a cylindrical interior,
a cartridge head (7) which closes one end of the tubular cartridge (1), a partition wall (2) arranged axially in the cylindrical interior of the cartridge (1), the partition wall (2) being in contact with the lateral surface of the cylindrical interior of the cartridge (1 wherein the partition wall (2) divides the cylindrical interior of the cartridge (1) bounded by the cartridge head (7) into two spatially separated cavities (3, 4), wherein in the first cavity (3) a first pasty cement component and in the separate second cavity (4) a second pasty cement component is contained, two axially in two cavities (3, 4) of the cartridge (1) slidably disposed discharge piston (5, 6), wherein the discharge piston (5, 6) the two cavities (3, 4) on the cartridge head (7) opposite side of the cavities (3, 4) complete,
wherein the discharge pistons (5, 6) are connected to one another at the rear side opposite the cartridge head (7) via a connecting means (18), wherein a wedge (22) or cone (22) with a cutting edge (20) is provided on the connecting means (18). on the cartridge head (7) facing the front of the wedge (22) or cone (22) is arranged so that when driving the discharge piston (5, 6) in the cavities (3, 4) in the direction of the cartridge head (7) the cutting edge (20) the partition (2) cuts open and the wedge (22) or cone (22) presses the cut parts (40) of the partition (2) in the direction of the inner wall of the cartridge (1). Storage and mixing system according to claim 1, characterized in that
the dividing wall (2) is connected to the lateral surface of the cylindrical interior of the cartridge (1) along two connecting lines bounding the lateral surface, the connecting lines preferably being arranged opposite each other and particularly preferably the axis of the cartridge (1) in the dividing wall (2 ) lies. Storage and mixing system according to claim 1 or 2, characterized in that
the cavities (3, 4) have a semicircular or circular segment-shaped cross-section, and the discharge pistons (5, 6) have a matching cross-section such that the discharge pistons (5, 6) close the cavities (3, 4) in any axial position in the cavities (3, 4). Storage and mixing system according to one of the preceding claims, characterized in that
the discharge pistons (5, 6) are spaced apart from one another via the connecting means (18) such that the gap lying between the discharge pistons (5, 6) is less than or equal to the thickness of the dividing wall (2). Storage and mixing system according to one of the preceding claims, characterized in that
the partition (2) has a maximum thickness of 1.5 mm, preferably of not more than 1.0 mm, and / or the partition wall (2) has such a thickness that the partition wall (2) with
the cutting edge (20) on which a driving force of 3 kN acts and to be bent by the wedge (22) or cone (22). Storage and mixing system according to one of the preceding claims, characterized in that
in the cartridge head (7) two bushings are provided, which connect the two cavities (3, 4) with the environment of the storage and mixing system, wherein in the bushings in each case a releasable plug (9) is arranged. Storage and mixing system according to one of the preceding claims, characterized in that
the cartridge (1), the cartridge head (7), the partition wall (2) and the discharge piston (5, 6) are made of plastic, wherein as plastics polyethylene co-vinyl alcohol (EVOH), polybutylene terephthalate (PBT), polyethylene terephthalate (PET ) and poly-methacrylic acid methyl ester-co-acrylonitrile are preferred. Storage and mixing system according to one of the preceding claims, characterized in that
the cartridge head (7) is realized by a rubber-elastic plate (7) which is fastened to the cartridge (1) with a cap (8), the cap (8) allowing movement of the rubber-elastic plate (7) from the cartridge (1 ) blocked away by means of a protruding edge, and wherein the rubber-elastic plate (7) on the discharge piston (5, 6) side facing a recess for receiving
the longitudinal side of the partition wall (2) has, and preferably by this Recording in the rubber-elastic plate (7) are defined two areas, wherein in each area a passage is arranged, which is closed by a plug (9). Storage and mixing system according to one of the preceding claims, characterized in that
a cap (8) is provided as a connecting element for connecting the cartridge head (7) with the cartridge (1), wherein the cap (8) has an internal thread (34) or an external thread or a bayonet closure or locking elements. Storage and mixing system according to one of the preceding claims, characterized in that
the connecting means (18) is designed such that the two cut - off parts (40) of the dividing wall (2) remain connected to the inner wall of the cartridge (1) when the connecting means (18) in the interior of the cartridge (1) move in the direction of Cartridge head (7) is driven. Method for mixing pasty cement components of a pasty cement paste, in particular a polymethyl methacrylate bone cement, with a storage and mixing system according to at least one of the preceding claims, characterized by the following successive steps, a) removing the cartridge head (7) from the cartridge (1) or removing at least two plugs (9) from at least two bushings in the cartridge head (7) so that the cartridge (1) is opened, b) placing and connecting a dispensing tube (28) to the opened cartridge (1), the dispensing tube (28) containing a mixer (30), c) inserting the cartridge (1) into a manually operated discharge device, the discharge device comprising an axially driven ram (48) for propelling the discharge pistons (5, 6) in the cavities (3, 4) of the cartridge (1), d) pressing out the pasty cement components by means of the discharge device by axially driving the discharge pistons (5, 6) with the plunger (48), whereby the cement components are pressed into the discharge tube (28), the two cement components being conveyed through the mixer (30) in the Discharge tube (28) are mixed to the paste-like cement dough and the mixed cement dough from a discharge opening (32) of the discharge tube (28) in which, in synchronism with the movement of the discharge pistons (5, 6), the dividing wall (2) is cut open by the cutting edge (20) in the longitudinal direction of the cartridge (1) and the two cut-open parts (22) or cones (22) 40) of the partition wall (2) in the direction of the inner wall of the cartridge (1) are pressed at least so far out that further movement of the plunger (48) of the discharge device is not prevented by the parts (40) of the cut-open partition (2) or is hampered. A method according to claim 11, characterized in that
the two cut-open parts (40) of the dividing wall (2) remain connected to the inner wall of the cartridge (1). Method according to one of claims 11 or 12, characterized in that the discharge pipe (28) with the cartridge (1) by connecting the connecting element (34) of the discharge pipe (28) with a connecting element (14) of the cartridge (1) is connected. Method according to one of claims 11 to 13, characterized in that
the ram (48) of the discharge device presses on the side (23) of the wedge (22) or cone (22) facing away from the delivery pistons (5, 6) and the discharge pistons (5, 6) via the wedge (22) or cone ( 22) and the connecting means (18) are driven. Method according to one of claims 11 to 14, characterized in that
the side (23) of the wedge (22) or cone (22) facing away from the discharge pistons (5, 6) has a contact surface (23) for applying the front side of the ram (48) or a plate attached thereto, which is the same size or larger is as the cross-section of the plunger (48) or as the bearing surface of the plate, wherein during the driving of the plunger (48) of the cross section of the plunger (48) or the support surface of the plate is completely covered by the contact surface (23) or preferably the contact surface ( 23) projects beyond the cross section of the plunger (48) or the bearing surface of the plate.

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